Control for a decelerating mechanism



M r 11,1958 R. D. DODGE 2,826,287

I CONTROL FOR A'DECELERATING MECHANISM 2 Shee'ts-Shet Filed Dec. 30,1954 INVENTOR. RONALD o. DODGE Isa Q monk- ATTORNEY March 11, 1958 R.DODGE 2,826,287

CONTROL FOR A DECELERATING MECHANISM Filed Dec. 50, 1954 FIG. 2

2 Sheets-Sheet 2 INVENTOR. RONALD 0.00005 M 6am? ATTORNEY United StatesPatent CONTROL son A DECELERATING MECHANISM Ronald D. Dodge,Poughkeepsie, N. Y., assignor to International Business MachinesCorporation, New York, N. Y., a corporation of New York ApplicationDecember 30, 1954, Serial No. 478,634 7 Claims. (Cl. 197-183) Thisinvention relates to movable carriage business machines and moreparticularly to an improved decelerating mechanism for absorbing shockwhile stopping a business machine carriage after afree or power drivenrun. One form of such decelerating mechanism is shown in my copendingapplication Serial No. 479,444, filedDecemher 29, 1954.

It is well recognized in the business machine art, particularly withtypewriters, that some sort of shock reduction means must be employed toreduce the noise and shock of the carriage when it is returned to itsleft hand margin position; or set free during a tabulation run. The artis replete with examples of snubbers and air cushions which operate toreduce shock and noise during these carriage functions, but there isstill need in the art for an improved speed sensitive deceleratingmechanism, that is, one which exerts a decelerating force that. isproportional to the speed of the carriage at the time the deceleratingforce is applied.

pointed out in the following description and claims and illustrated inthe accompanying drawings, which disclose, by way of example, theprinciple of the invention and the best mode which has been contemplatedof applying that principle.

In thedrawings: Fig. 1 is a perspective view of the rear of'the-wellfknownlBM typewriter, showing a linkage mechanism for actuating adecelerator.

Fig: 2 is a side elevation of the decelerating mechanism used during acarriage return.

Fig. 3 isa plan view of aportion of'the carr'iage'r'eturn deceleratingmechanism.

Fig.4 is a side elevation of the mechanism employed to decelerate thecarriage after a tabulation run. 'Br-iefly'this invention relates to adecelerator for a typewriter or business machine carriage wherein adecelerating cam is selectively interconnected with a power drivingmeans that will act to limit the movement of the cam; The cam isconnected through various linkages to the carriage of the businessmachine and during a tabulation or carriage return run, the linkagesystem is actuated tending to move the cam. The interengagement of thecam with the power driving means however limits the rate of movement ofthe cam and consequently'deceler-ates the business machine carriage.

Referring to the drawings and particularly to Fig. 1 a typewritercarriageis illustrated as having a margin rack-2, carrying a margin stop4 with the margin rack being movable with the carriage transverselyrelative to rails 6 one or which is shown.

Patented Mar. 11, 1958 In conventional typewriter installations as moreparticularly shown in copending application Serial No. 469,870, filedNovember 19, 1954, the typewriter is provided with a margin controllever or check 8 which is slidable within fixed limits (slots 9)relative to supporting studs 10 which'are secured to the typewriterframe. 'i he sliding of themar'gin check 8 is employed to rock a marginbell crank iz which is pivotally supported by the stud carried'bythetypewriter frame. More specifically as the margin stop 4is driven towardthe margin cheek -8 due to the carriage being returned to its left handmargin position, a blocking shoulder 16 of the margin stop 4 engagesacorresponding shoulder 18 of the margin check 8, thereby sliding thelatter to the left (as viewed in- Fig'.- 1) relative to the studs 10, torotate the margin bell crank 12 counterclockwise about its stud 14.

Conventional typewriters, as more particularly described in U. S. PatentNo. 1,935,436, to Dodge, are further provided with a-tabulating'systemwherein a tab lever 20 is positionedon the typewriter frame for pivotalmovementabout an axis indicated by the dot dash line 22. The pivotalmovement is in response to the operation of a tabulating power device(not shown) which acts to rock: a bellcrank 24 counterclockwise about apivot pin 26 thereby pushing on the right hand end of the tab lever 2bto rock it counterclockwise about the axis 22 so that its lefthand end28 will push a tab check lever 30 out from behind a bracket 32 freeingthe check lever 30 for movement to the left relative. to the tab leverwithin the limits of the slots 33. The tab check lever 30, is con- Inected to a crank arm 38 via a link 34.

The tab check lever Stl, when set in a checking position, is moreparticularly shown in U. S. Patent 1,935,436,

is engageable with a conventional tabulation stop of the "479,444,filed- December 29, 1954. When the carriage is actually stopped, themargin check 30 willhavebeen recocked to a rest position behind ashoulder (not shown.)

but carried by bracket 32.

The actionsof the rocking ofthe 'marginlever 12 about its pivot 14; andthe movement of thetab check 30 first to the left as the tab ,key of thetypewriter is-operated,

and. then to the right and back to the position shown in 'Fig. 1 as thetab. stop hits. the tab checkare employed respectively in conjunctionwitha corresponding.deceleratmg mechanism to slow down therate ofcarriage travel at the. end of either a t-abulating run or a carriagereturn operation.

Carriage return. decelerator The basic stiuctureof both'the carriagereturn decelerator and-'the tabnlating decelerator is substantiallyidenticah Specifically, these deceleratorshave segments or cams 44,: 46respectively whichfare supported coaxially about shafts 43, 50respectively which in turnare supported by brackets SZ, 54' respectivelywiththe brackets being pivotally supported about pin shafts -56, -Srespectively. The pin shafts'56, 58 are carried by supporting' brackets60, 62 respectively, which are mounted on the typewriter frame. The arms52, 54 carry integral stops 64,"68respectively'which are en-gageablewith set screws 70, 72. With this structure the shafts 48, 50 arepivotal about the pinshafts 56,58 from a position wherein the stop arms64, 63 are engageablewiththe screws-70, '72 to a counterclockwiselimitwherein the peripheries of sectors'44, 46 areinengagement with thecontinuously rotating power (In Figs. 2 and 4 the sectors are carried inturn by brackets 92, 94 which are secured to the typewriter frame. Links80, 82 respectively are provided with springs 81, 83 which are attachedto the frame to bias the pins 76, 78, and consequently the sectors 44,46 clockwise about their supporting shafts 48, 50.

As viewed in Figs. 2 and 4 the links 80, 82 are adjustably connected tothe bell cranks 84, 86 through adjustable bearings 96, 98 which aremovable in slots 100, 102 thereby varying the throw of the links 80, 82depending upon the radius of the bearings 96, 98 with respect to the pinshafts 88, 90.

In both the cafriage return and tabulating decelerator, a spring 104,166 respectively is employed to rock the arms 52, 54 to the clockwiselimit into engagement with the adjustable set screws 70, 72 therebybiasing the peripheries of segments 44, 46 normally out of engagementwith the power roll 74. The springs 104, 106 are normally tensioned butcan be collapsed to remove the clockwise rocking force on the arms 52,54. If either sector 44 or 46 is rotated counterclockwise as viewed inFigs. 2 and 4 with the springs 104 and106 under tension, then thesectors will simply rotate about their pin shafts 48, 59 and remainclear of the constantly rotating power roll 74. Such a rotation will beproduced by a force applied to the sectors 44, 46 through the links 80,82 respectively. If the tension in the springs 104, 106 has been relaxedhowever, then any force applied to the sectors 44, 46 through the links80, 82 will first rock the corresponding pin shafts 48, 50counterclockwise about their axes 56, 58 until the peripheral surfacesof the cams 44, 46 are individually brought into engagement with theperipheral surface of the power roll 74. The geometry of the. structure,then, once the sectors 44, 46 are brought into engagement with the powerroll, is such that so long as a force is continually applied through thelink 80 or 82 the corresponding sector will remain in engagement withthe power roll irrespective of the restoration of normal tension to thesprings 104, 106 respectively.

Based on this operating principle, and in order to utilize the actionfor the decelerators, the tension in springs 104, 106 must first becollapsed and then the corresponding bell cranks 84, 86 must be rockedcounterclockwise about the supporting pins 88, 90 through forces appliedby the links 108, 110 to bring the sectors 44, 46 respectively intoengagement with the power roll. Then because of the frictionalengagement between the peripheral surfaces of the sectors and the powerroll, the sectors will not be able to rotate counterclockwise abouttheir supporting shafts 48, 50 any faster than the peripheral speed ofthe power roll 74 will permit. This relationship limits the rate ofcounterclockwise rocking of the bell cranks 84, 86 and accordingly byconnecting the links 108, 110 to the bell cranks 38, 12 respectively, amechanism is provided to slow down the carriage after either carriagereturn operation or a tabulating operatlon.

In order to release the tension on spring 104 to initiate a deceleratingaction for a carriage return operation, the spring 104 is interconnectedbetween the bracket 52 and a bell crank 114 which is pivotally supportedabout a pin 116 carried by the typewriter frame. The bell crank isnormally biased counterclockwise by a spring 118 which is secured to aportion of the typewriter frame, but during a power carriage returnoperation, as more particularly explained in copending applicationSerial No. 469,870, filed November 19, 1954, a pull is exerted on a link120 by the carriage return cam thus rocking the bell crank 114 clockwiseabout its pivot 116. It is also explained in the copending applicationthat the clockwise rocking of hell crank 114 is utilized through theaction of the link 122 to lift the escapement pawls out of theescapement rack during a carriage return operation. It is obvious thatsince spring 104 is connected at the outer end of the bell crank 114,rocking the bell crank 114 clockwise about its pivot 116, will collapsethe spring 104 to relieve the tension on it. Accordingly it can beobserved that during a powered carriage return operation when theoperator depresses the well known carriage return button the link 120will first be pulled by the carriage return cam to rock the bell crank114 clockwise about its supporting pin 116 thereby lifting the pawls outof the escapement rack as heretofore mentioned, and, as the carriagereturn cam continues to rotate, the tension in spring 104 will becollapsed. It is well understood in the art that during a carriagereturn motion, -a tension tape (not shown) is employed and driventhrough a friction clutch to pull the carriage into its left hand marginposition. As the carriage goes into its left hand margin position, withfurther reference to Fig. 1, the margin stop 4 engages the margin check8 thereby rocking the bell crank 12 counterclockwise about itssupporting pin Fig. 2 the raising of link 108 will rock the bell crank84 counterclockwise about its support pin 88 thereby exerting a force onthe link and since the tension in spring 104 has been collapsed by bellcrank 114 sector 44 will be brought into engagement with the peripheryof the power roll 74 whereupon the continued counterclockwise movementof bell crank 84 as caused by the counterclockwise rocking of the bellcrank 12 (as viewed in Fig. 1) drives the sector 44 through a peripheralcontact cycle with the power roll 74. The peripheral speed of the powerroll 74 limits the rate of rotation of the sector 44 and also the rateof rotation of the bell crank 84 and consequently the rate of rotationof the bell crank 12. Since bell crank 12 is positively connected withthe carriage through a predetermined movement thereof (margin stop 4driving margin check 8) the interengagement of sector 44 and power roll74 acts to decelerate the carriage.

Tabulation decelerator With respect to the tabulating mechanism the bellcrank 86 is provided with an integral arm 128 and the spring 106 isinterconnected between the outer end of arm 128 and the bracket 54.Furthermore, the bell crank 86 is shown rotated to its clockwise limit,which action will release the tension in spring 106. When the bell crank86 is rocked counterclockwise about its supporting pin 90 the arm 128will be rocked counterclockwise about supporting pin 90 thereby puttingtension in the spring 106 to pull the bracket 54 to its clockwise limitinto engagement with the set screw 72.

It can be appreciated that the decelerator for the tab mechanism wouldbe operated somewhat differently from that for the carriage returnoperation. More specifically, it will be recognized that, in thecarriage return operation, .the bell crank 12 is simply movedcounterclockwise as driven by the interengagement of the margin stop 4and the margin check 8. However, in the tabulation operation the tabcheck lever 30 is first moved to the left under the control of the taboperation when the tab lever 20 is rocked counterclockwise about itsaxis 22. Then with the tab check 30 in the tab stop engaging positionthe carriage will be free in flight until one of the stops (not shown)which has been set in the tab check engaging position engages the tabcheck to drive it to the right from its Fig. 1 position to a normalposition where the left hand ends of the slots 33 are driven intoengagedecelerator as viewed in Fig. 4 is in its cocked position,

and in its normal position the sector 46 will have been rotatedapproximately 90 counterclockwise through a peripheral contact cyclethus lifting the link 110 to rock the bell crank 38 clockwise about itssupporting stud 40 so that the hell crank 38 acting through the link 34allows the tab check lever 30 to return to its normal position.

In operation of the tabulation decelerator then, the tab mechanism isfirst operated to release tab check lever 30 to its Fig. 1 position.This action rocks bell crank 38 counterclockwise to cock the tabulationdecelerator by pushing down on link 110 to rock bell crank 86 to itsFig. 4 position. As heretofore mentioned, this action will release thetension in spring 106 and'thus condition the decelerating mechanism toslow down the carriage after a tabulation run.

When the tab stop hits the tab check 30, link 82 acting through pin 78rocks pin shaft 50 about shaft 58 to bring sector 46 into peripheralcontact with power roll 74: Thereafter the rate of rotation of the powerroll controls the rate of rotation of sector 46 and hence the rate atwhich tab check 30 can be moved from Fig. 1 position to its normalposition.

With this structure, there is a direct driving relationship between thecarriage during a portion of a tabulating run and the decelerator. Hencethe carriage will be slowed down after a tabulation run with a minimumof noise and shock. Furthermore, in both the tabulating decelerator andthe carriage return decelerator the stopping force will be no greaterthan necessary to stop thecarriage.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to a preferredembodiment, it will be understood that various omissions andsubstitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in the artwithout departing from the spirit of the invention. It is the intention,therefore, to be limited only as indicated by the scope of the followingclaims.

What is claimed is:

1. In a power driven typewriter having power means and a carriagemovable across a printing position under the influence of a powerimparting means, a device for decelerating said carriage as it travelsthrough a predetermined distance comprising a cam, an arm supporting thesame for angular motion through an engaging cycle with said typewriterpower means between a start and finish position wherein the angularmotion of said cam is limited by said power means, means mounting saidarm for pivotal movement from an inactive limit wherein said cam cannotengage said power means to an active limit wherein said cam isengageable with said power means, and linkage means interconnecting saidcam and said carriage during movement of the latter through saidpredetermined distance to correspondingly move said cam from its startto finish position as said carriage moves through said predetermineddistance whereby said carriage acting through said linkage will drivesaid cam into engagement with said power means thereby limiting the rateof movement of said cam from its start to finish position andconsequently limiting the rate of movement of said carriage through saidpredetermined distance.

2. In a power driven typewriter having power means and a carriagemovable across a printing position under the influence of a powerimparting means, a device for decelerating said carriage as it travelsthrough a predetermined distance comprising a cam, an arm supporting thesame for angular motion through an engaging cycle with said typewriterpower means between a start and finish position wherein the angularmotion of said cam is 6 limited by said power'means, means *mountingsaidarm for pivotal movement from an inactive limit wherein said cam cannotengage said power meansto' an active limit wherein said cam isengageable with 'said power means, spring means biasing said armnormally to its inactive position, means responsive to the institutionof a carriage movement under its powerimparting means for collapsingsaid spring means to relieve its tension and thereby permit movement ofsaid arm to its active position, and linkage means interconnecting'saidcam and said carriage during movement of thelatter thr'oughsaidpredetermined distance to correspondingly move said cam from its startto finish position as said carriage moves through said predetermineddistance whereby after said spring means has been collapsed by theinstitution of a carriage movement said carriage acting through saidlinkage will drive said cam into engagement with said power meansthereby limiting the rate of movement of said cam from its start tofinish position and consequently limiting the rate of movement of saidcarriage through said predetermined distance.

3. In a power driven typewriter having a power roll and a carriagemovable across a printing position under the influence of a powerimparting means, a device for decelerating said carriage as it travelsthrough a predetermined distance comprising a cam of constant radius, anarm supporting the same for angular motion through a peripheral contactcycle with said power roll from a start to a finish position wherein theangular motion of said cam is limited by said power roll, means mountingsaid arm for pivotal movement from an inactive limit wherein said camcannot engage said power roll to an active limit wherein said cam canpass through said peripheral contact cycle with said power roll, andlinkage means interconnecting said cam and said carriage during movementof the latter through said predetermined distance to corr'espondinglymove said cam from its start to finish position as said carriage movesthrough said predetermined distance whereby said carriageacting throughsaid linkage will drive said cam intoengageinent with said power roll tolimit the rate of movement of said cam from its start to finish positionand consequently to limit the rate of movement of said carriage throughsaid predetermined distance.

4. In a power driven typewriter having power means and a carriagemovable across a printing position under the influence of a powerimparting means, a device for decelerating said carriage as it travelsthrough a predetermined distance comprising a cam of constant radius, anarm supporting the same for angular motion through an engaging cyclewith said typewriter power means between a start and finish positionwherein the angular motion of said cam is limited by said power means,means mounting said arm for pivotal movement from an inactive limitwherein said cam cannot engage said power means to an active limitwherein said cam is engageable with said power means, spring meansbiasing said arm normally to its inactive position, means responsive tothe institution of a carriage movement under its power imparting meansfor collapsing said spring means to relieve its tension and therebypermit movement of said arm to its active position, and linkage meansinterconnecting said cam and said carriage during movement of the latterthrough said predetermined distance to correspondingly move said camfrom its start to finish position as said carriage moves through saidpredetermined distance whereby after said spring means has beencollapsed by the institution of a carriage movement said carriage actingthrough said linkage will drive said cam into engagement with said powermeans to limit the rate of movement of said cam from its start to finishposition and consequently limit the rate of movement of said carriagethrough said predetermined distance.

5. In a power driven typewriter having a power roll and a carriagemovable across a printing position under the influence of a powerimparting means, a device for decelerating said carriage as it travelsthrough a predetermined distance comprising a cam, an arm supporting thesame for angular motion through a peripheral contact cycle with saidpower roll from a start to a finish position wherein the angular motionof said cam is limited by said power roll, means mounting said arm forpivotal movement from an inactive limit wherein said cam cannot engagesaid power roll to an active limit wherein said cam can pass throughsaid peripheral contact cycle with said power roll, and linkage meansinterconnecting said cam and said carriage during movement of the latterthrough said predetermined distance to correspondingly move said camfrom its start to finish position as said carriage moves through saidpredetermined distance whereby said carriage acting through said linkagewill drive said cam into engagement with said power roll to limit therate of movement of said cam from its start to finish position andconsequently to limit the rate of movement of said carriage through saidpredetermined distance.

6. In a power driven typewriter having a power roll and a carriagemovable across a printing position under the influence of a powerimparting means, a device for decelerating said carriage as it travelsthrough a predetermined distance comprising a cam of constant radius, anarm supporting the same for angular motion through a peripheral contactcycle with said power roll from a start to a finish position wherein theangular motion of said cam is limited by said power roll, means mountingsaid arm for pivotal movement from an inactive limit wherein said camcannot engage said power roll to an active limit wherein said cam canpass through said peripheral contact cycle with said power roll, springmeans biasing said arm normally to its inactive position, meansresponsive to the institution of a carriage movement under the influenceof its power imparting means for collapsing said spring means to relieveits tension and thereby permit movement of said arm to its activeposition, and linkage means interconnecting said cam and said carriageduring movement of the latter through said predetermined distance tocorrespondingly move said cam from its start to finish position as saidcarriage moves through said predetermined distance, whereby after saidspring means has been collapsed by the institution of a carriagemovement said carriage acting through said linkage will drive said caminto engagement with said power roll to limit the rate of movement ofsaid cam from its start to finish position and consequently limit therate of movement of said carriage through said predetermined distance.

7. In a power driven typewriter having a power roll and a carriagemovable across a printing position under the influence of a powerimparting means, a device for decelerating said carriage as it travelsthrough a predetermined distance comprising 'a cam, an arm supportingthe same for angular motion through a peripheral contact cycle with saidpower roll from a start to a finish position wherein the angular motionof said cam is limited by said power roll, means mounting said arm forpivotal movement from an inactive limit wherein said cam cannot engagesaid power roll to an active limit wherein said cam can pass throughsaid peripheral contact cycle with said power roll, spring means biasingsaid arm normally to its inactive position, means responsive to theinstitution of a carriage movement under the influence of its powerimparting means for collapsing said spring means to relieve its tensionand thereby permit movement of said arm to its active position, andlinkage means interconnecting said cam and said carriage during movementof the latter through said predetermined distance to correspondinglymove said cam from its start to finish position as said carriage movesthrough said predetermined distance whereby after said spring means hasbeen collapsed by the institution of a carriage movement said carriageacting through said linkage will drive said cam into engagement withsaid power roll to limit the rate of movement of said cam from its startto finish position and consequently limit the rate of movement of saidcarriage through said predetermined distance.

References Cited in the file of this patent UNITED STATES PATENTS

